Effect of ligustrazine on Gas/cAMP/PKA signal activity and airway inflammation in asthmatic rats / 中国药理学通报

ABSTRACT

Aim To investigate the effect of ligus- trazine on G-protein coupled receptor signal activity in ovalbumin ( OVA)-sensitized and challenged asthmatic rats.Methods This study replicated an OVA-in¬duced juvenile asthmatic rat model, and investigated the effect of ligustrazine on airway hyperresponsive- ness, airway inflammation, lung histopathology, IL-4, IL-5 , 1L-13 , TNF-cx levels in serum, cAMP concentra¬tion in plasma, CREB, PKA, Gas and GRK2 expres¬sion in lung tissues.Results It was showed that the resistance of lung (RL) in asthmatic rats increased, while the pulmonary dynamic compliance ( Cdvn) sig¬nificantly decreased ( P < 0.05 ) compared with the control rats, and the lung tissue injury was serious; the levels of IL-4, IL-5, IL-13, and TNF-cx in serum were significantly increased ( P <0.01 ).The cAMP level in plasma was reduced and the CREB and PKA expres¬ sions were down-regulated significantly ( P < 0.05 ).The Gas expression in lung in asthmatic rats was down- regulated while the GRK2 expression was up-regulated ( P <0.01 ).Ligustrazine coulrl improve the lung inju¬ry and lung function of asthmatic rats, decrease RL and increase Cdvn ( P < 0.05 ) , decrease the levels of 1L-4, 1L-5, 1L-13, and TNF-a in serum (P <0.01) , increase cAMP in plasma and up-regulate the PKA and CREB expression, down-regulate the GRK2 expression and up-regulate the Gas expression significantly ( P < 0.01).Conclusions The above study shows that li¬gustrazine can reduce the AHR, inhibit the inflamma¬tion in asthma, and the up-regulating of Gas/cAMP/ PKA signal activity may be its mechanism.